Dr. Pickron is recruiting babies for a study on language processing. She wants to study how 6-month old infants may be different from 9-month old infants. She goes to events for new parents and to daycares to recruit participants, making sure she recruits 30 for each group. What kind of sampling is this?
A quota sampling
B self-selection sampling
C stratified random sampling
D cluster sampling
The correct answer and explanation is:
The correct answer is A. quota sampling.
Explanation:
Quota sampling is a non-random sampling method where the researcher ensures that specific subgroups or characteristics within a population are represented proportionately in the sample. In this case, Dr. Pickron is recruiting two distinct age groups (6-month-old infants and 9-month-old infants) and making sure each group has 30 participants. This is done to meet a particular quota for each subgroup, which makes it a form of quota sampling.
Here’s why the other options do not fit:
- Self-selection sampling involves participants choosing to participate in the study, like when people respond to advertisements or volunteer for a study. In this case, Dr. Pickron is actively recruiting participants from events and daycares, rather than letting individuals choose to participate.
- Stratified random sampling is a method where the population is divided into subgroups, and random samples are taken from each subgroup to ensure proper representation. While Dr. Pickron is focusing on two age groups, she is not randomly selecting participants from each group. Instead, she recruits a fixed number from each group, which makes it different from stratified random sampling.
- Cluster sampling involves dividing the population into clusters (such as daycares or geographic regions) and then randomly selecting entire clusters. While Dr. Pickron is recruiting from daycares, she is not selecting entire clusters but rather individual participants from each cluster, making it not cluster sampling.
Therefore, Dr. Pickron’s approach is an example of quota sampling, where she specifically selects a set number of participants from each of the two age groups to ensure they are represented in her study.